Digestion-related problems are a frequent cause of general and social discomfort. These problems cover a diverse selection of gastrointestinal symptoms of which bloating, gas production, abdominal pain, overall discomfort, constipation, and loose stools are among the most frequent. Today many of the sufferers of such symptoms are believed to suffer from irritable bowel syndrome (IBS). IBS is clearly more frequent in women and it is believed to concern 10-20% of Western population; i.e. IBS is more frequent in Western population than lactose-intolerance (many people having lactose intolerance, though, might have IBS and vice versa).
Currently there is no good medical cure for IBS. Much attention has been paid on dietary management of IBS. Most attention has been paid on a diet called LOW-FODMAP diet. The idea of the diet is to avoid food items that contain FODMAP compounds. Term FODMAP is derived from “Fermentable, Oligo-, Di-, Monosaccharides, and Polyols”. FODMAPs are short chain carbohydrates and monosaccharides, which are poorly absorbed in the small intestine. FODMAP compounds include fructans (including FOS), galactans (especially GOS), and polyols. Also lactose and excess fructose can be considered as FODMAP compounds among people with impaired digestion or absorption of these compounds.
Common sources of fructans include for example wheat, rye, onion, Jerusalem artichoke, and garlic. Some examples of fructan contents of grains are as follows: rye (bran) 7% (on grain material basis), rye (grain) 3-7%, and wheat flour 1-4%. Although wheat is not generally considered as being especially rich in FODMAP compounds, its relatively high consumption makes it a relevant source of fructans. This is why the FODMAP diet guidelines instruct to avoid wheat. Rye consumption is high in Northern Europe. Rye bread contains more FODMAP compounds compared to wheat bread, because whole grain rye contains more fructans than wheat flour.
Fructans are built up of fructose residues, normally with a terminal sucrose unit (i.e. a glucose-fructose disaccharide). The linkage position of the fructose residues determines the type of the fructan. The basic types of single-linkage fructans are inulin and levan (or phlein). Additionally, there exists a mixed-linkage fructan called graminan.
Some prior art related to levels of fructan in bread is existing. In the article by Andersson et al. (2009) it was shown that the yeast fermented bread and especially the sourdough bread had lower contents of fructan as compared to whole grain rye flour. The results of Andersson et al. show that the fructan content of whole grain rye can be reduced from 5.0% to 1.9% by sourdough (62% reduction) and to 3.4% by yeast fermentation (32% reduction). The results also show that fructans are degraded during the bread-making process resulting in lower contents of total and extractable dietary fiber in the bread.
Article by Rakha et al. (2010) discloses that during bread making, the low-molecular weight fraction of fructan is most available for degradation by yeast or by endogenous enzymes present in the ingredients. According to Rakha et al., the fructan content in rye milling fractions ranges from 3.4% in inner endosperm to 5.0% in bran. The fructan content of rye breads varied from 1.9% to 4.0%, with an average of 2.8% in crisp breads, with a sample containing only whole grain rye flour being the highest in fructan content.
The dough according to US patent application US 2011/0129572 A1 comprises at least one fructose-containing polysaccharide and at least one enzyme capable of degrading said polysaccharide into short-chained fructo-oligosaccharide (FOS) and fructose. The baked product produced using this dough was said to have an increased softness compared to otherwise identical control bread or baked product produced using dough not containing the enzyme.
The discovery related to lowering the fructan amounts in plant material of patent application EP 1084624 A2 is that while Lactobacillus strains in general do not degrade fructan, there are Lactobacillus strains that do have this property. According to EP 1084624 A2, those strains are preferably Lactobacillus paracasei and Lactobacillus plantarum. 
Müller et al (1994) studied fermentation of fructans by epiphytic lactic acid bacteria. Strains of epiphytic lactic acid bacteria were isolated from forage grasses and their ability to hydrolyze fructans was studied. Only 16 out of 712 strains utilized fructans. Said strains were identified as Lactobacillus paracasei subsp. paracasei, Lactobacillus brevis and Pediococcus pentosaceus. 
As can be noted from above, some techniques to alter fructan levels are currently known and used. Additionally, it is known that sour bread has naturally lower levels of fructan. These fructan lowering techniques are generally based on using fermentation or specific fructan degrading enzymes.
Several fructan degrading enzymes are known in the art. Glycoside hydrolase family GH32 contains invertases and also enzymes that hydrolyze fructose containing polysaccharides such as inulinases, exo-inulinases, levanases and β-2,6-fructan 6-levanbiohydrolases, fructan β-(2,1)-fructosidase/1-exohydrolases or fructan β-(2,6)-fructosidase/6-exohydrolases, as well as enzymes displaying transglycosylating activities such as sucrose:sucrose 1-fructosyltransferases, fructan:fructan 1-fructosyltransferases, sucrose:fructan 6-fructosyltransferases, fructan:fructan 6G-fructosyltransferases and levan fructosyltransferases.
Extracellular enzymes such as inulinase that hydrolyze fructans are extracted for example from Aspergillus niger and are commercially available. These extracellular enzymes are naturally occurring enzymes that are isolated or extracted from their natural environments. However, these extracellular fructanase enzymes are expensive and difficult to obtain in sufficient amounts and high purity for large-scale applications.
For example, Paludan-Müller et al (2002) studied purification and characterization of an extracellular fructan β-fructosidase from a Lactobacillus pentosus strain isolated from fermented fish. An extracellular fructanhydrolase from Lactobacillus paracasei ssp. paracasei P 4134 was studied by Müller et al (1997), while Goh et al (2007) characterized a fructan hydrolase from Lactobacillus paracasei 1195. Document WO 2010/097416 A1 discloses a recombinant protein with fructanase activity comprising a fragment of a natural occurring protein derived from lactic acid bacteria such as Lactobacillus. 
Moreover, with the use of known fructan-degrading enzymes, such as endo-fructanase, inulinase, or levanase, there is a possibility that fructo-oligosaccharides (FOS) are formed as degradation products as by this means not all fructan is converted to fructose. Therefore, there is still a need for a specific fructan degrading enzyme (fructanase, fructan hydrolase) that is able to decompose fructans efficiently without formation of FOS.
FOS are carbohydrates that the human body cannot fully digest and can thus function as prebiotics. There are some positive effects suggested for FOS. For example, they may produce substances that stop the growth of harmful, toxic gram-negative and positive bacteria in the intestines. However, according to the currently available scientific evidence FOS can execute some harmful effects. FOS can cause e.g. bloating, flatulence, abdominal and intestinal discomfort, and eructation. Furthermore, people with lactose intolerance were shown to particularly suffer from these side effects. The reason for these symptoms may be that FOS are generally gastrointestinally more active than fructan polymer, since the intestinal microflora ferments them more rapidly. Moreover, fructose can also considered being a FODMAP-compound with people having impaired fructose absorption. This is a problem when no comparable amount of glucose is present in the food item or meal. This is because fructose absorption in human body occurs along with glucose-induced uptake system. The excess fructose concentration (vs glucose concentration) is, however, easy to tackle with food recipe or meal formulations.
What is still needed in the art are grain and vegetable materials that are substantially free of fructans and FOS and thereby can be used to prepare products that are suitable for low-FODMAP diets. What is also still needed in the art is an efficient method and means for fructan removal from grain and vegetable material that would not result in unfavorable degradation products, especially FOS. Therefore, a method and means that would enable the efficient removal of fructan would be very beneficial for the development of food products suitable for low-FODMAP diet. Consumption of these food products would not cause gastrointestinal problems. Said food products could even have a positive effect on gastrointestinal health and in that way on general wellbeing.